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Fig. 1

Calculation of ion contribution to growth. a The average relative electrostatic enhancement 4(β±0/β00)(N0/Ntot) between ions and aerosols of diameter d (solid line). The dotted line is (β±0/β00), and the dashed line is (N0/Ntot). b The relative size of the ion condensation, Γ (Eq. (6)) in %, in an atmosphere with a condensible gas concentration of 1 × 106 molecules cm−3 as a function of aerosol diameter d and ionization rate q (left hand axis) or ion density (right hand axis). The contour lines show the relative size of the growth due to ion condensation in % of the usual condensation growth. The mass ratio (mion/m0) is set to 2.25, and the mass of the neutral molecule is set to 100 AMU